New guidelines did not change mammography rates

NEW YORK (Reuters Health) - The proportion of women undergoing screening for breast cancer every year did not change after a government-backed panel said women in their 40s shouldn't have routine mammograms, according to a new study.

In 2009, the U.S. Preventive Services Task Force (USPSTF) recommended that women aged 50 to 74 have a mammogram every other year and said for younger women, screening should be an individual decision by each woman with her doctor.

That's because the benefits of screening only slightly outweigh harms from overdiagnosis and unnecessary treatment and any potential benefits are smaller in younger women, according to Dr. Michael LeFevre, co-vice chair of the Task Force.

LeFevre, who is also a family medicine doctor at the University of Missouri School of Medicine in Columbia, said he didn't find the new results all that surprising.

"It would be optimistic to think the lack of change reflects the decision by many women in their 40s to go ahead and proceed with mammography with a clear understanding of the benefits as well as the risks," he told Reuters Health.

"I think it is a bit more likely that physicians continue to recommend mammography without necessarily discussing the specifics of what the science tells us," said LeFevre, who wasn't involved in the new study. "It's always easier to do than to discuss."

Dr. Lydia Pace from Brigham and Women's Hospital in Boston and her colleagues analyzed nationally-representative surveys of close to 28,000 women, age 40 and older, from 2005, 2008 and 2011. Among other things, women were asked if they'd had a mammogram in the past year.

Overall, there was no clear change in screening rates after the USPSTF's recommendation: 53.6 percent of all women said they'd recently had a mammogram in 2011, compared to 51.9 percent in 2008.

Mammography rates did not change in any age group. Among women in their 40s, 47.5 percent had been recently screened as of 2011, compared to 46.1 percent in 2008.

Some professional organizations, such as The American College of Obstetricians and Gynecologists, still recommend regular screening for women as young as 40 - and surveys suggest many doctors favor that approach.

"When there are conflicting versions of guidelines, providers may err on the side of screening," said David Howard, a health policy researcher from Emory University in Atlanta who has studied mammography.

One of the issues is that both individual women and guideline-making groups may weigh the benefits and harms of mammography differently, researchers said.

Some may accept any risk for a small chance of catching breast cancer early, whereas others will weigh the harms of infection and bleeding from biopsies, for example, more heavily.

Howard said that over time, there may be a shift toward fewer women in their 40s having mammograms.

Because the guidelines are relatively recent, "A lot of women in that age group turned 40 with the expectation that they would get a mammogram every year or every other year," Howard, who also wasn't part of the new research team, told Reuters Health.

"I think it's a harder thing to stop screening if you've already started," Pace agreed. "That could account for some of the lack of decline."

However, she told Reuters Health, "Given how widespread the publicity was about these recommendations, I think most providers were certainly aware of them, and we would have expected to see some changes we didn't see."

Researchers said women in their 40s should be fully informed about the benefits and risks of screening before deciding to have a mammogram.

"For younger women," Pace said, "the decision to undertake mammography screening is one that is not necessarily taken lightly."

"Be aware that there is some benefit - the benefit is quite small, there are some risks and that a personal decision is absolutely to be honored," LeFevre said.